<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <title>测试</title>
</head>
<body style="padding-left: 50px">
   <h1>字符串</h1>

   <h2>1.字符串常用内建函数</h2>
   <div>
       <ul>
           <#assign a = 'hello '/>
           <#assign b = 'world'/>
           <li>
               连接: <font color="red">${a + b}</font>
           </li>
           <li>
               截取: <font color="red">${(a + b)?substring(5, 8)}</font>
           </li>
           <li>
               长度: <font color="red">${(a + b)?length}</font>
           </li>
           <li>
               大写: <font color="red">${(a + b)?upper_case}</font>
           </li>
           <li>
               小写: <font color="red">${(a + b)?lower_case}</font>
           </li>
           <li>
               index_of: <font color="red">${(a + b)?index_of("w")}</font>
           </li>
           <li>
               replace: <font color="red">${(a + b)?replace("o", "xx")}</font>
           </li>
       </ul>
   </div>
</body>
</html>